That's mainly been the configuration since training camp began, and it's mostly been the way it's been composed since the Saints game. But the 49ers also are experimenting from time to time with different linups, which you might see at times in Saturday's game against the Raiders.

Said Jim Harbaugh on Tuesday: "We're doing some of that in practice now, for two reasons: One is that all offensive linemen need to play their position and be ready to play the opposite side, like the opposite tackle or a guard that can play center or vice versa. We do a lot of that for versatility. And the second reason is to see what the combinations are for the best five."

The new combinations have Jonathan Goodwin at center, Snyder at right guard in place of Rachal and Alex Boone at right tackle instead of Davis. On Monday, offensive coordinator Greg Roman said one of the reasons for the different looks was "really continencies in case there were injuries" to the starters. Still, as most 49ers observers will attest, Rachal and Davis struggled the most of all the team's linemen last season.

Boone, who had a strong game playing left tackle on the second-team unit against the Saints, was asked Tuesday whether he thought he could start for the 49ers.

"I would like to," Boone said. "But obviously I've got to take great strides to get there. Just keep working. Just keep practicing ... At the end of the camp, I guess you would hope to be among the best five."

MATTHEW BARROWS

Matt was born in Blacksburg, Va., and attended the University of Virginia. He graduated in 1995, went to Northwestern for a journalism degree a year later, and got his first job at a South Carolina daily in 1997. He joined The Bee as a Metro reporter in 1999 and started covering the 49ers in 2003. His favorite player of all time is Darrell Green.